dupre



Feb. 7, 1956 R. E. DUPRE 2,734,115

ELECTRICAL SWITCHES Filed May 12, 1955 3 Sheets-Sheet l man A INVENTOPROLAND E. DUPRE.

ATTOR EV Feb. 7, 1956 R. E. DUPRE ELECTRICAL SWITCHES 5 Sheets-Sheet 2Filed May 12, 1955 INVENTOR ROLAND E.. bupma Feb. 7, 1956 R. E. DUPREELECTRICAL SWITCHES 3 Sheets-Sheet 3 Filed May 12, 1953 INVENTOR ROLANDE. DUPPJ;

ATTORNEY United States Patent v ELECTRICAL SWITCHES Roland E. Dupre,Fiskdale, Application May 12, 1953, Serial No. 354,475

8 Claims. (Cl. 200--168) This invention relates to improvements inelectrical circuit switches and has particular reference to theprovision of novel and inexpensive constructions of switches wherebyonly the portions thereof most susceptible to wear and requiringreplacement may be readily interchanged or replaced.

One of the principal objects of the invention is to provide a circuitswitch of the above character whereby only the portions thereof mostsusceptible to wear can readily be interchanged or replaced with easeand simplicity and without having to disturb the connections of saidswitch with the main line circuit.

Another object is to provide an outer housing having contact plates forrelatively permanent connection with a main line circuit and an innerhousing embodying a plurality of switch blades having portions thereofadapted to automatically electrically engage the contact plates whensaid inner housing is positioned in said outer housing, said innerhousing embodying an adjustable contact member which when in oneposition of adjustment will close a circuit through certain of saidswitch blades and when in another position of adjustment will close acircuit through other of said switch blades, said inner housing havingmeans for securing it in said outer housing, said means being such as toenable the inner housing to be adjusted outwardly of said outer housingan amount sufficient to disengage the portions of said switch bladesfrom their respective contact plates prior to the complete removal ofsaid inner housing from said outer housing whereby the inner housing andthe portions of the switch blades therein may be interchanged Withouthaving to disconnect the main contact plates from the main line circuitand with no danger of receiving an electrical shock.

Another object is to provide a novel switch lever construction which issimple and durable in construction, positive in function and silent inoperation.

Another object is to provide a switch of the above character which maybe readily converted to a single pole, three-way or four-way switch asdesired and with a minimum change of parts.

Another object is to provide a novel method of making circuit bladeelements for a switch of the character described and of supporting saidcircuit blade elements in proper position of use whereby they may bereadily interchanged or replaced by other circuit blade elements whendesired.

Other objects and advantages of the invention will become apparent fromthe following description taken in connection with the accompanyingdrawings and it will be apparent that many changes may be made in thedetails of construction, arrangement of parts and method shown anddescribed without departing from the spirit of the invention asexpressed in the accompanying claims. I, therefore, do not wish to belimited to the exact details of construction, arrangement of parts andmethod shown and described as the preferred form only has been given byway of illustration.

ice

Referring to the drawings:

Fig. I is a plan view of the device embodying the invention;

Fig. II is a side elevational View of said device;

Fig. III is a bottom plan view of the outer housing of the device;

Fig. IV is a perspective view of the outer housing showing the circuitcontact members and circuit terminals associated therewith;

Fig. V is a top plan view of a contact plate;

Fig. VI is a face view of said contact plate;

Fig. VII is a perspective View showing how the con` tact plate issecured to a circuit terminal;

Fig. VIII is an exploded diagrammatic perspective view of the innerhousing having a portion of its side wall broken away and showing itscorrelated parts;

Fig. IX is a perspective view of an insulation or filler member utilizedwith the device embodying the invention;

Fig. X is a plan view of a blade circuit element formed in accordancewith the invention;

Fig. XI is a plan View of another circuit element formed in accordancewith the invention; and

Fig. XII is an enlarged fragmentary sectional view taken as on lineXII-XII of Fig. I.

In following the teachings of the invention, and for ease ofdescription, a four-way switch is shown in the drawings and will bedescribed in detail hereinafter.

The switch construction comprises an outer housing It? preferably formedof Bakelite, plastic, or other suitable material having a plurality ofT-shape slots 1i formed in opposite side walls thereof, the siots 11each having an open side area 12 communicating with the interior of thehousing. inwardly of said slots 11 there is positioned contact members13 comprising a pair of preshaped portions 14 and 15 adapted to befolded in superimposed relation with each other, as shown in Fig. VII.The said portion 14 is provided with a plurality of shallow channels 16each having a corrugated or roughened inner surface. The portion 14 isof a size and shape to fit within the slots 11 with the portion 15 beingof a size and shape to lie within the open areas 12. The portion 15 isalso provided with a corrugated or roughened surface 17 and when folded,as shown in Fig. VII, is adapted to clamp the bared end 18 of a mainline circuit wire 19 therebetween. The free edge of the portion 15 isresilient whereby it will be slightly free to move toward the portion 14when pressure is exerted thereon.

A contact plate 13 is positioned in each of the slots 11 with theportion 15 thereof extending outwardly of the respective open area 12.With a switch construction, such as shown in Fig. VIII and which is afour-way switch, a Contact plate 13 is positioned in the outer housingadjacent the lower end of each of the opposed slots to form a pair oflow positioned contact plates, as illustrated in Fig. IV. The otheropposed `slots 11 each have Contact plates 13 positioned thereinadjacent the tops of said slots to provide a pair of upper contactplates 13. It is to be understood that each contact plate is connectedwith a main circuit line. The spaces in said slots 11 unoccupied by thecontact plates 13 are provided with a filler 29 of Bakelite, plastic orother suitable material such as shown in Fig. IX. In the case of theupper contact plates, the contacts 13 are first placed inwardly of theslots 11 prior to the insertion of the filler 20 in said slots while inthe case of the lower contact members the fillers of insulation materialare inserted in the slots 11 prior to the insertion of the contactplates The fillers 20 are so dimensioned as to retain said contactplates in desired positions in said slots, see Fig. IV.

It is particularly pointed out that the contact plates 13, that is, theportions 14 and 15 thereof, when folded to clamp the bared end 18 of thecircuit wire therein, as shown in Fig. VII, are so dimensioned as tohave a re1- ativcly intimate iit in the respective slots 11 with theportions 15 thereof extending slightly outwardly of the open areas 12.

The inner housing 25 is dimensioned and shaped to t within the outerhousing 10. The side walls of the inner housing, as shown in Fig. VIII,are provided with spaced cnt-out areas 26, 27, 28 and 29. Each of thewall sections, intermediate said cut-out areas, is channeled, asillustrated at 39, throughout the length thereof and substantially tothe depth of said cutout areas to receive the supporting plates 32, 33,35 and 37 and the associated parts of the lower contact blade circuitelements of the device. The supporting plate 32 is connected by a lead49 to a contact blade 5t). It is further connected by a lead l to thesupporting plate 35 which, in turn, is connected through the lead 57 toa Contact blade 58. The housing 25 is provided, in its respective endwalls, with slots 73 and 74 communicating with the respective channeledportions 30 of the cut-out areas 26, 28, 27 and 29 to receive therespective leads 49 and 5'? of one circuit element and to receive theleads 52 and 55 of another circuit element. The leads 52 and 5S arerespectively connected to the contact blades S3 and 56 and thesupporting plates 33 and 37. The said supporting plates 33 and 37 are,in turn, connected by the lead 54. The bottom of the housing 25 isprovided with grooves 62 and 63 for receiving the respective leads 51and 54 therein.

It is pointed out that the above described blade circuit elementsconstitute the lower circuit units of the device, one unit having asubstantially reversed Z shape and the other a substantially Z shape.The rst unit embodies, for example, a blanked out structure as shown inFig. X comprising contact blades 5l)au and 58a adjacent the outer freeends of the leads 49'l and 57a which constitute the upper and lowerbranches of the reversed Z, supporting plate portions 32a and 355L onthe opposed ends of said branches and an angularly disposed lead 51ELconnecting said supporting plate portions and which constitute theangled central portion of the Z. The cooperative elements of the unitare blanked from sheet beryllium copper or other conductive material.The various portions of the first unit are thence bent to theconguration illustrated in Fig. VIII. This is accomplished by bendingthe portions 32a, 35a, 50ZL and 58a in a sidewise and upward directionand simultaneously to the shape desired of the respective portions 32,35, 50 and 58. The second Z-shaped unit is formed by merely turning theblanked out unit over and bending the portions thereof as set forthabove whereby the supporting plates 32m-35a will then become thesupporting plates 33-37, the angularly disposed connecting lead 51 willthen become 54, the respective leads 4921-57a will become leads 52--55,and the contact blades 50M-58a will become contact blades 53-56.

The intermediate inner portions of the end walls are each provided withvertically slotted areas 75l and 76 having their side edges taperinginwardly to communicate with the respective slots 73 and 74, as shown inFig. VIII. The respective vertically slotted areas 75 and 76 are adaptedto receive the respective contact blades Sil-53 and 56-58 when therespective supporting plates 32, 33, 35 and 37 are positioned within therespective cut-out areas 26, 27, 28 and 29. The leads 49, 52, 55 and 57assume a position inwardly of the slots 73 and 74 in the end walls andthe contact blades 50-53 and 56-58 will assume a position in overlyingrelation with the inwardly beveled edge walls of the intermediatevertically slotted areas 75 and 76.

Suitable spacers, such as shown in Fig. XI, may be placed inwardly ofthe slotted portions 30 of the respective open areas 26, 27, 28 and 29above the respective supporting plates 32, 33, 35 and 37 when positionedtherein.

Another set of circuit elements 77, such as shown in Fig. XI, areblanked from sheet beryllium copper or other conductive material andcomprise portions 31a and 34a connected by a lead 43a and by leads 39ELand 45a to Contact blade portions 45a and 46a. The said portions 31a and34a are bent in a sidewise and upward direction and simultaneously tothe shapes illustrated in Fig. VIII to form the supporting pcrtions31-34 each having an outwardly angled intermediate portion and opposedaligned tongue portions. The portions 4lla-46a are bent downwardly toform the blade portions 40-46. The leads 39a, 43a and 45a form therespective leads 39, 43 and 45. This circuit element is placed inwardlyof the respective open areas 26 and 27 with the lead 43 tted in the slot71 intermediate said open areas and the respective leads 39 and 45fitting within the slotted ends 73 and 74. The contact blades 4t) and 46which are bent downwardly, as illustrated in Fig. VIII, are adapted tofit within the respective vertically slotted areas 75 and 76 inoverlying relation with the adjacent angled edge surfaces or" saidslotted areas. A similar circuit element is formed with the exceptionthat the portions 312L and 34a and the contact blades 46a and 46il arebent in the opposite direction. The element is then reversed to form therespective supporting plates 36 and 38 connecting lead 44 and leads 4land 47 which are connected to the contact blades 42 and This section isplaced inwardly of the respective open areas 28 and 29 with the lead 44lying in the slot 72 intermediate said areas, with the leads 41 and 47lying within the adjacent slots 73 and 74 and with the contact blades 42and 48 lying within the respective vertical slots 75 and 76 and inoverlying relation with the adjacent angled edge surfaces thereof.

Suitable spacer members of insulation material may be placedintermediate the various end leads 49-52 and 39-41 to hold them inproper spaced relation with each other and between the respective leads55-57 and 45-47 to hold them in proper spaced relation with each other.If desired, ller members of insulation material may be placed above thevarious supporting plates 31, 34, 36 and 38 and the respectiveconnecting leads to anchor them in proper position in the inner housing25. It is to be understood that the liller members are so dimensionedthat the upper edges thereof will be substantially llush with therespective upper edges of said inner housing 25.

The leads 51 and 54 have an insulation strip or plate 67 positionedtherebetween so as to insulate one of said leads from the other at thelocation where they cross each other. The insulation strip 67 isdimensioned to tit within spaced upwardly extending substantiallyparallel rib portions 64 and 65 formed on the inner bottom surface ofthe inner housing and which extend transversely of said housing toAcommunicate with the respective vertically slotted areas 75l and 76. Aplate of insulation material similar to the plate 67 is positioned inbetween said ribs 64 and 65 in overlying relation with the leads 51 and54 to form a guideway for reeciving an adjustable blade contactingmember 66. The respective opstanding ribs 64 and 65, as shown at 78, 79,and 3l are cut away to provide clearance for the respective leads 5l and54.

The adjustable blade contacting member 66, as shown in Fig. VIII,comprises a pair of relatively flat strips of beryllium copper or otherconducting material 82 and 83 having their respective ends 84-85 and86-87 provided with a V-shaped bend adapted to engage the respectivecontact blades 40-50 and 42-53 at one end of the housing when adjustedin the direction thereof and the ends 85-87 are adapted to engage therespective contact blades 46-56 and 48-58 when adjusted in the directionthereof. The said portions 82 and 53 are spaced relative to each otherby suitable strips 83 and S9 of insulation material and are held inassembled relation with each other by a pin 90 fitting within bushingsof insulation material 91 and 92 frictionally placed in suitableopenings centrally of the portions 82 and 83. The inner ends of thestrips 88 and 89 of insulation material are spaced relative to eachother to receive the depending portion 93 of a switch lever 94. Thedepending portion 93 is provided with a slot 95 adapted to straddle thepin 9,0 when the depending portion 93 is placed in the spaced areabetween the strips of insulation material 88 and 89. A coil spring 96 isplaced on said depending portion 93 prior to placing said dependingportion in assembled relation withthe pinl90. The said switch lever 94is provided on the opposed sides thereof with outwardly extendingportions 97 each having an integrally related pin portion 98 thereon.The said pin portions 98 are adapted to p iit within suitable curvednotches 99 formed in the upper side walls of the inner housing 25.

The pin portions 98 of the switch lever 94 are held within said curvednotches 99 by a metal plate or cap 1,00 which has a central slot 101therein through which the lever 94 extends and which has dependinghsideportions 102 each having on the opposed ends thereof bendableprojections 103 adapted to be bent so as to be within notches 115 formedin the ends of the inner housing 25. The depending side portions 102 areangled slightly inwardly with respectto each other and adapted lto frictionally engage the inwardly angled recessed opposed sides 104 of thehousing 25. The plate or cap 100 is provided on its opposed ends withtongues 105 each having a connection opening 106 therein for` receivingconnection screws 107 by means of which the inner housing 25 is securedinternally of the outer housing 10, see Fig. 1. Each of the end walls ofthe housing' 10 is provided with a vertically disposed metal bushing 21extending throughout the height thereof and having a threaded bore 22adapted to receive the screws 107. The housing 25 is dimensioned to havea loose sliding fit internally of the housing and when positionedtherein the various supporting plates 31--32, 33-34, 35-36and 37-38 areadapted to frictionally and electrically engage with the contactelements 13 placed inwardly of the respective open areas 26, 27, 28 and29. In this instance, however, only the lower supporting plates 32 and37 will engage the respective portions of the lower Contact elements 13positioned within the slotted kand open areas 11 and 12 and which are,in turn, connected with the circuit terminals 19, and only thesupporting plates 34 and 36 will engage, the portions 15 of the uppercontact members 13 in the respective slotted and cut-out areas 11 and 12in the opposed end of the housing andwhich are, in turn, connected withthe electrical leads 19. rThe inner housing is held in the outer housingby tightening the screws 107. The screws 107 beneath the perforatedtongues 105 are provided with washers 108 in mechanically lockedrelation therewith. The opposed upper edges of the housing 10 are cutaway, as shown at 109,l to provide clearance for the washers 108. TheWashers 108 are so interlocked with the screws 107 as to permit saidscrews to be turned and yet retain their initially related position onsaid screws beneath the tongues 105. This is for the purpose of causingthe inner housing 25 to move in a direction outwardly. of the outerhousing 10 when the respective screws 107 are .backed out and the saidscrews 107 are of a length suiiicient to permit the respectivesupporting plates which were in initial contact with the portions 15 ofthe contact members 13 out of engagement with said respective contactmembers whereby the inner housing may then be lifted out of the outerhousing without danger of having the individual performing thisoperation receiving an electrical shock. In this manner the innerhousing and associated parts thereof, namely, the circuit contact bladesand associated parts thereof, may be interchanged as desired withouthaving to replace the other parts of the device. This enables theContact blades, which are the partsmost susceptible to wear to bequickly and easily interchanged or replaced when desired. The outerhousing 10 is provided inwardly thereof with a vertically disposed key23 adapted to fit within a vertically disposed groove 24 formed in theinner housing whereby the said inner housing may be polarized with theouter housing.

The outer housing, as shown in Figs. I and Il, is provided with slotsadapted to receive the side portions 111 of a supporting bracket 112.The supporting bracket is provided with a spanning member 113 which isadapted to overlie plate of insulation material 114 fitting over thelower end of the outer housing 10. The side portions 111 may be securedto the housing by rivets, screws, or other suitable means. The bracket112 is of the conventional type.

It is to be understood that by proper selection and positioning of thecontact members 13 in the outer housing 10 and by proper arrangement ofblade circuits the characteristics of the resultant switch may bechanged. For example, if it is desired to form a three-way switch acircuit element such as 77 would be placed in one side oi the innerhousing 25, that is, the support plates 31-34 would be placed in therespective open areas 26-27 with the leads 39-45 and lead 43 lyingwithin the respective slots 73-74 and 71. However, the other section ofthe circuit would be like 77 with the central lead 4?:a omitted. Thesecircuit elements would be placed in the other side of the inner housing25 with the support plate 38 lying in the open area 29, the lead 41lying in the slot 73 and the blade 42 lying in the vertical slot 76. Thesupport plate 36, which is now separate from the support plate 38, lieswithin the open area 28 and the lead 47 lies within the slot 74 and thecontact blade 48 lies within the vertical slot 75. The Contact blades40-42 of said circuit elements will assume an overlying relation withthe inwardly beveled edge surfaces of the vertical slot 76 and theblades 46-48 will assume an overlying relation with the beveled edges ofthe slot 75. In this instance only the above circuit elements are used.The above circuit elements will now be at the bottom of the open areas26-27 and 28-29. Contact members 13 are now placed only in the slottedand open areas 11-12 of the outer housing 10 so as to engage only therespective supporting plates 31, 36 and 38, that is, only three maincircuit connections 19 are required.

The adjustable contact 66 is now formed without the insulation bushings91-92 whereby the pin 90 which is of metal will close an electricalcircuit through both sections 82-83.

For a single pole switch only two halves of the circuit element 77 wouldbe used, that is, two elements each embodying only the portions 31a, 39aand 40a. These two half circuits now embody only the supporting plate31, lead 39 and contact blade 40 on one side of the inner housing 25 andthe supporting plate 3S, lead 41 and contact blade 42 on the other sideof the housing.

Only two Contact members 13 and two main circuit connections 19 areused, these being placed in the outer housing 10 to engage with therespective supporting plates :iL-38. The adjustable contact 66 is thesame as that described for the three-way switch. it is to he understood,of course, that suitable fillers or spacers 20 will be used to ll theempty areas and the unoccupied portions of the open areas and slots aspreviously described.

It is to be understood, of course, that the blade circuit portions wouldbe formed by blanking in a manner similar to the circuit portionsillustrated in Figs. X and XI and to have the proper characteristicsdesired.

From the foregoing description it will be seen that simple, eihcient andeconomical means and method have been provided for accomplishing all ofthe objects and advantages of the invention.

Having described my invention I claim:

l1. A device of the character described comprising an outer housinghaving solid continuous side walls with inwardly disposed recessescommunicating with slots extending inwardly of said side walls throughan end edge surface thereof, said slots being disposed in a planeparallel with said side walls within the limit of the thickness of saidside walls and said recesses having areas of a width less than the widthof the slots and an inner housing having recesses in the side wallsthereof with slots in the side edges of said recesses, said innerhousing being shaped to slidingly t within said outer housing, each ofsaid housings having contact members formed with edge portions slidablymounted in the slots in the walls thereof and each having a relativelyiiat intermediate portion lying in said recesses and extending outwardlythereof an amount sufiicient to assume a frictional and an electricalengagement with each other when said inner housing is placed in saidouter housing and means for securing said inner housing in said outerhousing, the Contact members of said outer housing being adapted to haveelectrical connection with the leads of a main line circuit, and theContact members of said inner housing being adapted to have electricalconnection with switch mechanism supported in said inner housing,whereby the switch mechanism will be energized by engagement of saidcontact members of the outer housing with the contact members of theinner housing and will permit said switch mechanism to be deenergized bymovement of the inner housing outwardly of the outer housing withoutdisconnection of the contact members of said outer housing from theleads of the main line circuit, said Contact members in the recesses ofsaid outer housing and the exposed portions of the leads connectedthereto being located within and shielded by the solid continuous wallsof said outer housing and from electrical contact with means externallyof said solid walls.

2. A device of the character described comprising an outer housinghaving solid continuous walls with slots extending inwardly thereoffroln one end edge of said housing, said slots being disposed in a planeparallel with said side walls within the limit of the thickness of saidside walls, the inner walls of said slots each having a recesscommunicating with the interior of the housing and being of a width lessthan the width of the slots, and an inner housing having recesses in theside walls thereof located to communicate with the recesses in the outerhousing and having slots in the opposed sides thereof, said innerhousing being shaped to slidably it within said outer housing, each ofsaid housings having contact members formed with edge portions slidablymounted in the slots and each having a relatively flat intermediateportion lying in said recesses and extending outwardly thereof an amountsuiiicient to assume a frictional and an electrical engagement with eachother when said inner housing is placed in said outer housing and meansfor securing said inner housing in said outer housing, the contactmembers of said outer housing being adapted to have electricalconnection with the leads of a main line circuit, and the contactmembers of said inner housing being adapted to have electricalconnection with switch mechanism supported in said inner housing,whereby the switch mechanism will be energized by engagement of saidcontact members of the outer housing with the contact members of theinner housing and will be de-ener gized by movement of the inner housingoutwardly of the ou ter housing without disconnection of the contactmembers of said outer housing from the leads of the main line circuit,said Contact members in the recesses of said outer housing and theexposed portions of the leads connected thereto being located within andshielded by the solid continuous walls of said outer housing and fromelectrical contact with means externally of said solid walls.

3. A device of the character described comprising an outer housinghaving side walls with internally disposed recesses therein eachcommunicating with a slot extending inwardly of an edge surface of saidside wall in substantially parallel relation therewith and of a widthgreater than the Width of said respective recesses and an inner housingshaped to slidingly fit within said outer housing, and having recessesin the side walls thereof aligned with the recesses in said outerhousing and having slotted edges on the opposed sides of said recesses,said outer housing having contact members formed with edge portionsslidably mounted in the slots and relatively flat intermediate portionslying in the recesses thereof, and extending slightly outwardly of saidrecesses, leads connecting said contact members with a main linecircuit, the said contact members and the exposed portions of said leadsbeing shielded by the side walls of said outer housing and from possibleaccidental electrical contact with conductive means externally of theouter housing, said inner housing having contact members formed withedge portions slidably mounted in the slots of the side walls thereofand each having a relatively flat intermediate portion lying in saidrespective recesses and extending outwardly thereof an amount sufcientto frictionally engage the relatively flat side surfaces of theintermediate portions of the contact members in said outer housing whensaid inner housing is slidably fitted in said outer housing, saidContact members of said inner housing having an electrical connectionwith switch mechanism supported in said inner housing and saidfrictional Contact of the Contact members of the inner housing with thecontact members in the recesses internally of the side walls of theouter housing being such that the inner housing may be moved outwardlyof said outer housing and the contact members out of frictionalengagement with each other without disconnection of the contact membersof said outer housing from the leads of the main line circuit.

4. A device of the character described comprising an outer housinghaving contact plates supported by the side walls thereof with portionsof said plates exposed inwardly of the housing, one set of Contactplates being located adjacent the lower end of said housing and anotherset being located adjacent the upper end of said housing, said contactplates being adapted to have the leads of an electrical circuit attachedthereto, an inner housing having open areas in the opposed side wallsthereof adapted to communicate with the contact plates in the outerhousing,

a first set of supporting plates secured in said open areas, one pair ofsaid plates having a portion thereof engaging the contact platesadjacent the lower end of the outer housing when said inner housing islocated therein, contact blades supported in horizontally spacedrelation with each other at each end of the inner housing, electricalleads connecting each of said contact blades with a respective adjacentsupporting plate in each of the respective side walls of the innerhousing, electrical cross leads connecting one of each of the respectivesupporting plates adjacent one end of the opposed side walls of theinner housing to the oppositely disposed respective supporting plates insaid side walls and adjacent the opposed end of said inner housing, anelectrical lead connecting each of the respective supporting plates insaid opposed side walls of the inner housing, a second set of supportingplates positioned in the respective open areas in the inner housing,means for insulating said second set of supporting plates from said rstset of supporting plates, one pair of said second plates having aportion thereof in engagement with the respective set of contact platesadjacent the upper end of said outer housing, a second pair ofhorizontally spaced Contact blades adjacent the opposed end of saidinner housing, means for insulating said second set of spaced contactblades from the first-mentioned spaced contact blades, electrical leadsconnecting each of said contact blades with a respective adjacentsupporting plate of said second set in said open areas of the innerhousing, electrical leads connecting the respective supporting plates ofsaid second set on each of the opposed sides of the inner housing, amovable Contact member slidably supported in said inner housing, saidmovable contact member comprising two electrical conductive membersinsulated from each other and each having their respective end portionsshaped to simultaneously and separately engage a respective pair of theupper and lower horizontally spaced blade portions adjacent the opposedends of the housing to close an electrical circuit through saidrespective upper and lower blade portions when said movable contactmember is moved in the direction of engagement with said contact blades,and a switch lever operably connected with said movable contact memberand embodying means for retaining the ends of said spaced electricalconductive members of said movable contact member in adjusted engagementwith the contact blades adjacent one end or the other of said innerhousing.

5. A device of the character described comprising an outer housinghaving side walls with continuous uninterrupted outer surfaces, saidside walls having slots extend ing inwardly thereof from one end of thehousing, the inner walls of said slots each having a cut-out areacommunicating with the interior of the housing, and an inner housinghaving recesses in the side walls thereof located to communicate withthe recesses in the inner side walls of the outer housing, said sidewalls of said inner housing further having slotted areas intermediatethe recesses and communicating therewith, slots in each of the end wallsof said inner housing communicating with a vertically disposed long andnarrow recess in the inner intermediate portion of said end walls,spaced switch blades in said long and narrow recesses, said innerhousing being shaped to slidingly fit within said outer housing, each ofsaid housings having contact members mounted in the recesses in the sideWalls thereof adapted to assume a frictional and an electricalengagement with each other when said inner housing is placed in saidouter housing and means for securing said inner housing in said outerhousing, the contact members of said outer housing being adapted to haveelectrical connection with the leads of a main line circuit, and thecontact members of said inner housing and the switch blades supported insaid vertically disposed long and narrow recesses in the innerintermediate portion of the end walls of said inner housing beingadapted to have electrical connection with each other through electricalleads lying within said slots in the side and end walls of said innerhousing, whereby the switch blades will be energized by engagement ofsaid contact members of the outer housing with the contact members ofthe inner housing outwardly of the outer housing without disconnectionof the contact members of said outer housing from the leads of the mainline circuit.

6. Blade circuit elements for an electrical switch of the characterdescribed comprising substantially reversed Z-shape members ofconductive material having the upper and lower portions thereof, whichconstitute the upper and lower branches of the Z, each formed with anintegral enlarged end joined with long and narrow sections which areintegrally connected with substantially right angularly disposedenlarged rectangular portions, each of said rectangular portions beingintegrally joined with a long and narrow angularly disposed intermediateportion which constitutes the intermediate portion of the Z.

7. A blade circuit element of conductive material having a substantiallyC-shape embodying upper and lower portions having enlarged ends joinedby reduced substantially parallel integral portions to right angularlydisposed enlarged rectangular portions which are, in turn, integrallyjoined with a reduced intermediate long and narrow portion.

8. A device of the character described comprising an outer housinghaving side walls with continuous uninterrupted outer surfaces andinternally disposed recesses communicating with slots extending inwardlyof an end edge thereof, said slots being disposed in a plane parallelwith said side walls within the limit of the thickness of said sidewalls and said recesses having areas of a width less than the Width ofthe slots, and an inner housing shaped to slidingly fit within saidouter housing, and having recesses in the side walls thereof with slotsin the opposed sides of said recesses and aligned with the recesses insaid outer housing, said outer housing having relatively dat contactmembers mounted in the internal recesses thereof and having sideportions slidably fitted in the slots communicating with said recesses,leads connecting said contact members with a main line circuit, the saidcontact members and the exposed portions of said leads being shielded bythe side walls of said outer housing and from possible accidentalelectrical contact with conductive means externally of the outerhousing, said inner housing having contact members mounted in therecesses of the side walls thereof and having side portions slidablyfitted in the opposed slotted sides 'of said recesses, said contactmembers of said inner housing having an electrical connection withswitch mechanism supported in said inner housing and having frictionalcontact with the Contact members in the recesses internally of the sidewalls of the outer housing whereby the inner housing may be movedoutwardly of said outer housing and the contact members out offrictional engagement with each other without disconnection of thecontact members of said outer housing from the leads of the main linecircuit.

References Cited in the file of this patent UNITED STATES PATENTS1,977,078 Mener Oct. 16, 1934 2,367,441 Schwinn Jan. 16, 1945 2,531,350Chrastina Nov. 21, 1950

